Mug lid



FIG. 1 is a front left side perspective view of my new design;

FIG. 2 is a rear, right side perspective view;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view;

FIG. 5 is a rear elevational view;

FIG. 6 is a front elevational view;

FIG. 7 is a right side view; and,

FIG. 8 is a left side view.

The ornamental design for a mug lid, as shown and described.